Java：更容易漂亮的打印？
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Java: Easier pretty printing?
提问by Nick Heiner
At the end of my computations, I print results:
在我的计算结束时，我打印结果：
System.out.println("\nTree\t\tOdds of being by the sought author");
for (ParseTree pt : testTrees) {
conditionalProbs = reg.classify(pt.features());
System.out.printf("%s\t\t%f", pt.toString(), conditionalProbs[1]);
System.out.println();
}
This produces, for instance:
这会产生，例如：
Tree Odds of being by the sought author
K and Burstner 0.000000
how is babby formed answer 0.005170
Mary is in heat 0.999988
Prelim 1.000000
Just putting two \tin there is sort of clumsy - the columns don't really line up. I'd rather have an output like this:
只是把两个\t放在那里有点笨拙 - 列并没有真正对齐。我宁愿有这样的输出：
Tree Odds of being by the sought author
K and Burstner 0.000000
how is babby formed answer 0.005170
Mary is in heat 0.999988
Prelim 1.000000
(note: I'm having trouble making the SO text editor line up those columns perfectly, but hopefully you get the idea.)
（注意：我无法让 SO 文本编辑器完美地排列这些列，但希望您能理解。）
Is there an easy way to do this, or must I write a method to try to figure it out based on the length of the string in the "Tree" column?
有没有一种简单的方法可以做到这一点，或者我必须编写一种方法来尝试根据“树”列中字符串的长度来找出它？
回答by falstro
You're looking for field lengths. Try using this:
您正在寻找字段长度。尝试使用这个：
printf ("%-32s %f\n", pt.toString(), conditionalProbs[1])
The -32 tells you that the string should be left justified, but with a field length of 32 characters (adjust to your liking, I picked 32 as it is a multiple of 8, which is a normal tab stop on a terminal). Using the same on the header, but with %sinstead of %fwill make that one line up nicely too.
-32 告诉您该字符串应该左对齐，但字段长度为 32 个字符（根据您的喜好进行调整，我选择了 32，因为它是 8 的倍数，这是终端上的正常制表位）。在标题上使用相同的内容，但使用%s而不是%f将使其排列得很好。
回答by Carl Smotricz
What you need is the amazing yet free format().
您需要的是惊人而免费的format()。
It works by letting you specify placeholders in a template string; it produces a combination of template and values as output.
它的工作原理是让您在模板字符串中指定占位符；它产生模板和值的组合作为输出。
Example:
例子：
System.out.format("%-25s %9.7f%n", "K and Burstner", 0.055170);
%sis a placeholder for Strings;%25smeans blank-pad any given String to 25 characters.%-25smeans left-justify the String in the field, i.e. pad to the right of the string.%9.7fmeans output a floating-point number with 9 places in all and 7 to the right of the decimal.%nis necessary to "do" a line termination, which is what you're otherwise missing when you go fromSystem.out.println()toSystem.out.format().
%s是字符串的占位符；%25s表示将任何给定的字符串空白填充到 25 个字符。%-25s表示将字段中的字符串左对齐，即填充到字符串的右侧。%9.7f表示输出一个总共9位，小数点右边7位的浮点数。%n要“做”一个线路终端，这是你当你走的时候，否则会丢失System.out.println()到System.out.format()。
Alternatively, you can use
或者，您可以使用
String outputString = String.format("format-string", arg1, arg2...);
to create an output String, and then use
创建一个输出字符串，然后使用
System.out.println(outputString);
as before to print it.
像以前一样打印它。
回答by Jonathan Feinberg
How about
怎么样
System.out.printf("%-30s %f\n", pt.toString(), conditionalProbs[1]);
See the docs for more information on the Formatter mini-language.
有关Formatter mini-language 的更多信息，请参阅文档。
回答by S.Lott
回答by daniel_or_else
Using j-text-utilsyou may print to console a table like:
使用j-text-utils您可以打印控制台，如：
And it as simple as:
它很简单：
TextTable tt = new TextTable(columnNames, data);
tt.printTable();
The API also allows sorting and row numbering ...
API 还允许排序和行编号......
